The invention relates to devices for the insertion of catheter guidewires into blood vessels. A guidewire is inserted so that a catheter, which is coaxially engaged with the guidewire, may be inserted into the blood vessel. The guidewire is then withdrawn, and the catheter is ready for further positioning and use. It is imperative that guidewires be inserted without contamination of the sterile field to avoid unnecessary infection of the patient.
Guidewires are generally comprised of a coiled spring guide with a distal tip and one or more wires running longitudinally within the spring. Such guidewire constructions are disclosed in U.S. Pat. Nos. 4,003,369 and 4,676,249. Catheters are generally hollow, flexible tubes used to convey liquids or other instruments to a desired location in the body.
Existing systems for guidewire insertion suffer from continued problems arising from the lack of ease in manipulation and the exposure during insertion to a non-sterile environment. Normally, a guidewire is removed completely from its package prior to use, is wound in the physician's hand and inserted through a needle extending into the patient's artery, or through a cannula into some other body cavity. Three or more hands are required to hold the needle stationary while the "J" guidewire is pulled through a straightener, then pushed through the port in the needle. The inadvertent extension of the guidewire prior to insertion and the awkwardness of manipulation during insertion leads to contamination of the sterile field and the patient's blood stream. It is also desirable that the physician or operator be able to tactilely sense the progress of the guidewire tip during insertion to insure better control.